Lack of physical activity (PA) is associated with obesity, diabetes, hypertension, cardiovascular diseases, and cancer. Parenting practices influence PA in young children. However, there is little evidence available for adolescents. We examined whether parenting practices were associated with out-of-school PA (OSPA) in US adolescents. This cross-sectional 2019 study analyzed data from the 2014 FLASHE study, a web-based, quota-sampled survey of parent-adolescent dyads. Inclusion required survey completion and parents to live with their teen (ages 12-17y old). Physically limited adolescents were excluded. Dyads were stratified by teen age. Exposures included parental modeling, monitoring, facilitation, restriction, guided choice, and pressure. The outcomes of interest were OSPA Youth Activity Profile scores. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated using adjusted logistic regressions. A total of 1109 dyads were included. Guided choice increased odds of OSPA for 15- to 17-year-olds (OR = 2.12; 95% CI, 1.17-3.84). Facilitation increased odds of OSPA for 12- to 14-year-olds (OR = 2.21; 95% CI, 1.13-4.33). Monitoring decreased odds of OSPA for 15- to 17-year-olds (OR = 0.34; 95% CI, 0.20-0.57) and 12- to 14-year-olds (OR = 0.45; 95% CI, 0.27-0.74). Friend support increased odds of OSPA in 15- to 17-year-olds (OR = 4.03; 95% CI, 2.29-7.08) and 12- to 14-year-olds (OR = 3.05; 95% CI 1.69-5.51). Future interventions should prioritize (1)shared decision making for older teens, (2)access to PA opportunities for younger adolescents, and (3)promoting peer PA and friend support for everyone.